Irtysh vs Irtish

Irtysh and Irtish both are nouns.

Word	Noun	Adjective	Verb	Adverb
Irtysh	Yes	No	No	No
Irtish	Yes	No	No	No

As nouns, Irtysh and Irtish are synonyms defined as:

Irtysh and Irtish: an Asian river that rises in the Altai Mountains in northern China and flows generally northwest to become a tributary of the Ob River

Other synonyms of Irtysh include Irtish River, Irtysh River.

Irtysh (noun)	Irtish (noun)
an Asian river that rises in the Altai Mountains in northern China and flows generally northwest to become a tributary of the Ob River	an Asian river that rises in the Altai Mountains in northern China and flows generally northwest to become a tributary of the Ob River